The Rotation of the Pacific Plate Induced by the Ontong Java Large Igneous Province

The eruption of large igneous provinces usually has major geodynamic influences on overriding plates. Seamount chains indicate that the drifting direction of the Pacific Plate changed by similar to 80 degrees in the Early Cretaceous when the Ontong Java Plateau formed. This, however, is not fully consistent with the magnetic anomalies. Here we show that there is an angle of similar to 25 degrees between the magnetic anomaly lines M-0 and 34 of both the Japanese and the Hawaiian lineations, suggesting that the orientations of both spreading ridges changed by roughly the same angle towards the same direction. The configurations of the Shatsky Rise, the Papanin Ridge and the Osbourn Trough suggest that the eruption of the Ontong Java plume head uplifted the southeastern corner of the Pacific Plate, and pushed its east part northward by similar to 700 km within 2 Ma. Meanwhile, the west part of the Pacific Plate was subducting southwestward underneath the eastern Asian Continent. These two forces together rotated the Pacific Plate anticlockwisely by ca 50 degrees. Consequently, the drifting direction of the Pacific Plate also changed from southwestward to northwestward, which plausibly explains the ca 80 degrees bending of the Shatsky Rise and the Papanin Ridge. The ridge between the Pacific and the Izanagi/Kula plates was pointed towards the similar to 300 degrees orientation, whereas the Pacific Plate was subducting towards the similar to 250 degrees orientation before similar to 125 Ma, and towards similar to 280 degrees afterward.

Automated summary

The eruption of large igneous provinces has significant geodynamic effects on overriding plates. Seamount chains indicate a change in the drifting direction of the Pacific Plate during the Early Cretaceous. Magnetic anomalies also suggest changes in the orientations of spreading ridges. The eruption of the Ontong Java plume head uplifted the southeastern corner of the Pacific Plate and pushed its eastern part northward. Meanwhile, the western part of the Pacific Plate was subducting beneath the eastern Asian Continent. These forces combined to rotate the Pacific Plate anticlockwise and change its drifting direction.